Regulation of hepatocyte cAMP and pyruvate kinase by site-specific analogs of adenosine.
Regulation of hepatocyte cAMP and pyruvate kinase by site-specific analogs of adenosine.
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腺苷位点特异性类似物对肝细胞 cAMP 和丙酮酸激酶的调节。
DOI：
10.1016/0303-7207(82)90116-2
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发表时间：
1982
影响因子：
4.1
通讯作者：
Johnson,RA
中科院分区：
文献类型：
--
作者：
Olaus,TH;Anand-Srivastava,MB;Johnson,RA
本文研究了腺苷的位点特异性类似物对离体大鼠肝细胞cAMP含量和丙酮酸激酶活性的影响。N6-（苯基异丙基）腺苷（PIA）是一种代谢稳定的腺苷类似物，其特异性作用于“R”位点，增加cAMP含量和降低丙酮酸激酶活性的程度与肾上腺素相当。相比之下，腺苷本身没有影响。与“R”位点介导的作用一致，PIA的作用被3-异丁基-1-甲基黄嘌呤阻断。2′，5 ′-二脱氧腺苷特异性地作用于P位点抑制腺苷酸环化酶，可抵消肾上腺素对丙酮酸激酶的作用，但矛盾的是不能抵消PIA的作用。腺苷酸环化酶在膜从这些实质细胞进行了测定，并被发现表现出相当的敏感性，'R'位点特异性类似物和其他激活剂一样，从整个肝脏制备的酶。因此，数据表明，对肝脏代谢的腺苷的“R”位点特异性类似物的影响是由腺苷酸环化酶的腺苷受体偶联激活启动的，并且这些影响是实质细胞的特征。
The effects of site-specific analogs of adenosine on cAMP content and pyruvate kinase activity of isolated rat hepatocytes were studied.N6-(Phenylisopropyl)adenosine (PIA), a metabolically stable analog of adenosine which acts specifically at ‘R’ sites, increased cAMP content and decreased pyruvate kinase activity to about the same extent as did epinephrine. By contrast, adenosine itself was without effect. Consistent with ‘R’-site mediated effects, the effects of PIA were blocked by 3-isobutyl-1-methylxanthine. 2′,5′-Dideoxyadenosine, which acts specifically at ‘P’ sites to inhibit adenylate cyclase, counteracted the effects of epinephrine on pyruvate kinase, but paradoxically not the effects of PIA. The adenylate cyclase in membranes from these parenchymal cells was determined and was found to exhibit comparable sensitivity to ‘R’ site-specific analogs and other activators as did the enzyme prepared from whole liver. Thus, the data suggest that the effects on liver metabolism of ‘R’ site-specific analogs of adenosine are initiated by an adenosine-receptor coupled activation of adenylate cyclase and that these effects are characteristics of the parenchymal cells.